Minor change to fcall allocation in preparation for fs2.c/libixp2

cmd/wm/fs.c

@@ -662,13 +662,17 @@ static char *
 xwalk(IXPConn *c, Fcall *fcall)
 {
 	IXPMap *m;
+	char *err;
 	unsigned int qsel, nwqid;
 	PackedQid wqid[IXP_MAX_WELEM], *qid;
 
-	if(!(m = ixp_server_fid2map(c, fcall->fid)))
-		return Enofile;
-	if(fcall->fid != fcall->newfid && (ixp_server_fid2map(c, fcall->newfid)))
-		return Efidinuse;
+	if(!(m = ixp_server_fid2map(c, fcall->fid))) {
+		err = Enofile;
+		goto Fail;
+	}if(fcall->fid != fcall->newfid && (ixp_server_fid2map(c, fcall->newfid))) {
+		err = Efidinuse;
+		goto Fail;
+	}
 
 	for(qsel = 0; qsel < m->nwqid; qsel++)
 		wqid[qsel].qid = m->wqid[qsel];
@@ -691,8 +695,10 @@ xwalk(IXPConn *c, Fcall *fcall)
 		fcall->wqid[nwqid] = wqid[qsel].qid = qid->qid;
 	}
 
-	if(fcall->nwname && !nwqid)
-		return Enofile;
+	if(fcall->nwname && !nwqid) {
+		err = Enofile;
+		goto Fail;
+	}
 
 	/* a fid will only be valid, if the walk was complete */
 	if(nwqid == fcall->nwname) {
@@ -708,10 +714,14 @@ xwalk(IXPConn *c, Fcall *fcall)
 		m->sel = qsel;
 		m->fid = fcall->newfid;
 	}
+	free(fcall->wname[0]);
 	fcall->id = RWALK;
 	fcall->nwqid = nwqid;
 	ixp_server_respond_fcall(c, fcall);
 	return nil;
+Fail:
+	free(fcall->wname[0]);
+	return err;
 }
 
 static char *

libixp/convert.c

@@ -91,6 +91,29 @@ ixp_pack_string(unsigned char **msg, int *msize, const char *s)
 		ixp_pack_data(msg, msize, (void *)s, len);
 }
 
+void
+ixp_unpack_strings(unsigned char **msg, unsigned short n, char **strings) {
+	unsigned char *s = *msg;
+	unsigned int i, size = 0;
+	unsigned short len;
+	/* XXX: a specially crafted packet could make this read past the end of the buffer */
+	for(i=0; i<n; i++) {
+		ixp_unpack_u16(&s, &len);
+		s += len;
+		size += len + 1; /* for '\0' */
+	}
+	/* XXX: we don't really need mallocz here */
+	s = cext_emallocz(size);
+	for(i=0; i < n; i++) {
+		ixp_unpack_u16(msg, &len);
+		memcpy(s, *msg, len);
+		s[len] = '\0';
+		strings[i] = s;
+		*msg += len;
+		s += len + 1;
+	}
+}
+
 void
 ixp_unpack_string(unsigned char **msg, char *string, unsigned short stringlen,
 		unsigned short *len)

libixp/ixp.h

@@ -132,7 +132,7 @@ typedef struct {
 	unsigned char mode;			/* Tcreate, Topen */
 	unsigned int newfid;			/* Twalk */
 	unsigned short nwname;			/* Twalk */
-	char wname[IXP_MAX_WELEM][IXP_MAX_FLEN];/* Twalk */
+	char *wname[IXP_MAX_WELEM];/* Twalk */
 	unsigned short nwqid;			/* Rwalk */
 	Qid wqid[IXP_MAX_WELEM];		/* Rwalk */
 	unsigned long long offset;		/* Tread, Twrite */
@@ -145,6 +145,7 @@ typedef struct {
 typedef struct IXPServer IXPServer;
 typedef struct IXPConn IXPConn;
 typedef struct IXPMap IXPMap;
+typedef struct Intmap Intmap;
 
 struct IXPMap {
 	IXPMap *next;
@@ -154,6 +155,20 @@ struct IXPMap {
 	Qid wqid[IXP_MAX_WELEM];
 };
 
+typedef struct Intlist	Intlist;
+struct Intlist
+{
+	unsigned long	id;
+	void*	aux;
+	Intlist*	link;
+};
+
+struct Intmap
+{
+	unsigned long nhash;
+	Intlist	**hash;
+};
+
 struct IXPConn {
 	IXPConn *next;
 	int fd;
@@ -210,6 +225,7 @@ void ixp_unpack_u32(unsigned char **msg, unsigned int *val);
 void ixp_pack_u64(unsigned char **msg, int *msize, unsigned long long val);
 void ixp_unpack_u64(unsigned char **msg, unsigned long long *val);
 void ixp_pack_string(unsigned char **msg, int *msize, const char *s);
+void ixp_unpack_strings(unsigned char **msg, unsigned short n, char **strings);
 void ixp_unpack_string(unsigned char **msg, char *string,
 		unsigned short stringlen, unsigned short *len);
 void ixp_pack_data(unsigned char **msg, int *msize, unsigned char *data,
@@ -225,6 +241,14 @@ void ixp_unpack_qid(unsigned char **msg, Qid *qid);
 void ixp_pack_stat(unsigned char **msg, int *msize, Stat *stat);
 void ixp_unpack_stat(unsigned char **msg, Stat *stat);
 
+/* intmap.c */
+void initmap(Intmap *m, unsigned long nhash, void *hash);
+void freemap(Intmap *map, void (*destroy)(void*));
+void* lookupkey(Intmap *map, unsigned long id);
+void* insertkey(Intmap *map, unsigned long id, void *v);
+int caninsertkey(Intmap *map, unsigned long id, void *v);
+void* deletekey(Intmap *map, unsigned long id);
+
 /* message.c */
 unsigned short ixp_sizeof_stat(Stat *stat);
 unsigned int ixp_fcall2msg(void *msg, Fcall *fcall, unsigned int msglen);

libixp/message.c

@@ -179,8 +179,7 @@ ixp_msg2fcall(Fcall *fcall, void *msg, unsigned int msglen)
 		ixp_unpack_u32(&p, &fcall->fid);
 		ixp_unpack_u32(&p, &fcall->newfid);
 		ixp_unpack_u16(&p, &fcall->nwname);
-		for(i = 0; i < fcall->nwname; i++)
-			ixp_unpack_string(&p, fcall->wname[i], IXP_MAX_FLEN, &len);
+		ixp_unpack_strings(&p, fcall->nwname, &fcall->wname);
 		break;
 	case RWALK:
 		ixp_unpack_u16(&p, &fcall->nwqid);